DAVIE, Fla. -- Former University of Tulsa H-back Charles Clay waited until his third NFL season to take a handoff for the Miami Dolphins, and when the play was called, he knew exactly what to do.

"Just hold onto the ball," Clay thought to himself.

Which he did, scoring a touchdown. But the Dolphins' offense hasn't always been that simple for the versatile Clay, who needed a couple of seasons to get comfortable playing multiple positions.

Now he's a starter at tight end, an H-back at times and an occasional fullback. He's also a big reason Miami is off to a 2-0 start for only the second time since 2002.

"He's definitely playing with a lot of confidence right now and has come into his own, doing things without any hesitation," offensive coordinator Mike Sherman said. "In the past maybe he wasn't 100 percent sure what he was doing."

That's understandable, because there was a lot to learn. Now Clay's busier than ever filling the role that had been planned for tight end Dustin Keller, who suffered a season-ending knee injury a month ago.

Productivity at the position is improved over recent seasons. Ryan Tannehill has targeted Clay 13 times, and 10 of those passes have been completed for 163 yards. In Sunday's victory at Indianapolis, Clay gained 109 yards - the second-highest total ever for a Miami tight end - on five receptions, including a 67-yard gain to set up a touchdown.

"He's a fast guy, and he showed it," Tannehill said. "He's huge for us. We knew when we lost Keller, he was going to have to step up and play a big part of our offense."

In the season opener Clay took 62 snaps on offense, a career high. He took 53 against Indy. Along with playing tight end, he lines up in the slot or backfield, and sometimes goes in motion.

"There's a lot on his plate," Sherman said.

Clay's first career rushing attempt came Sunday as a fullback when he scored on a 1-yard plunge.

"I don't know if he will be compared to Jim Brown or anything," coach Joe Philbin said with a smile, "but he did a good job."

Clay played tailback and fullback at Tulsa. He also played linebacker, defensive end, tight end, H-back, wide receiver and wildcat quarterback. He scored 10 touchdowns rushing and 28 receiving.

"I'm just a guy who's going to do whatever it takes - catching the ball, blocking if they need me to," he said. "I'm just trying to help the team."

A sixth-round draft pick by Miami in 2011, Clay spent his first two NFL seasons backing up Anthony Fasano at tight end, and he had 34 receptions for 445 yards and five scores.

Fasano never totaled more than 41 catches in any of his five seasons with the Dolphins, but now that they have the speedy Mike Wallace at receiver to open up the middle of the field, tight end could become a more productive position.

While Clay has showed he's capable of impressive statistics, he also must block, and that remains an area of concern.

"In this last game we really challenged him to be a better blocker," Sherman said, "and he really contributed in run blocking, and also as a pass blocker."

Tannehill had time to throw to Wallace for the first touchdown at Indy only because Clay picked up a blitzing rusher. Such an assignment is just part of Clay's extremely long job description.

"We're getting a lot out of him," Philbin said. "Hopefully he can continue to contribute and improve."